Due to different traveled paths and changing conditions on the network, during packet transmission over a network, packets may be received with a jitter and at a varying rate.
Media delivery systems, which use an IP network, are prone to jitter introduction due to the asynchronous nature of packet switching in the IP network. This jitter must be managed and overcome by IP reception devices, using for example a jitter buffer and sophisticated algorithms. A big problem facing the IP reception devices is the small amount of buffer allocated for the management of jitter. Since IP networks are expected to grow as time progresses, additional jitter to that of the original jitter in the network can be expected, so that an IP reception device may not be capable of providing the necessary jitter buffer.
Jitter control is a mandatory requirement of media systems based on the MPEG transport specification. Failure to control jitter causes media to exhibit undesirable visual and audio artifacts to the end user. It is a task of the network infrastructure to remedy packet jitter by enhancing the quality of service in the network; but this is very difficult to achieve in a media delivery network.
FIG. 1 illustrates a Prior Art System for transmitting media packets. A transmitter 11 sends packets 11P at a fixed rate and with a minimal jitter through the network 12. The received packets 11R, after passage through the network 12, may have a different delay between packets, resulting in packet jitter, as well as a varying rate. These phenomena may detrimentally affect the performance of the receiver 13.